Extended Data Fig. 2: Sample fabrication process.
From: One-dimensional Luttinger liquids in a two-dimensional moiré lattice
a, Cartoon illustrations of a prepared top graphite/hBN stack (top) and a flake of monolayer WTe2 on a SiO2/Si chip (bottom). Their corresponding optical images are also shown to the right. The distance between the aligned graphite edge and hBN edge is carefully optimized during transfer to be within 500 nm. b & c, Tear the monolayer WTe2 by the hBN into two separate pieces, labelled as top and bottom WTe2. d, Rotate the bottom WTe2 flake, i.e., the SiO2/Si chip, counterclockwise by θ. e, Pick up the bottom WTe2 to create a tWTe2 stack. The optical image of the tWTe2 stack shown to the right was taken after flipping the stamp upside down. The tWTe2 stack is highlighted by the red dashed line. No visible bubbles were observed. f, The pre-patterned bottom part (thin hBN/Pd electrodes/hBN dielectric/graphite) with etched holes in the thin hBN layer to expose the tips of the Pd electrodes (see ref. 16,17). An atomic force microscope image shows a clean surface of a prepared bottom stack. g, The final stack of a tWTe2 device, with an optical image of a final device (no. 1). The thickness of flakes is 7.6 nm graphite/8.9 nm top hBN/WTe2/2.0 nm thin hBN/5.5 nm bottom hBN/ 7.0 nm graphite for device no. 1 and 4.8 nm graphite/10.6 nm top hBN/WTe2/4.2 nm thin hBN/15.0 nm bottom hBN/ 6.9 nm graphite for device no. 2. All scale bars are 3 μm.
